feat(tests): implement Phase 2 integration testing - workflow creation tests

Implements comprehensive workflow creation tests against real n8n instance
with 15 test scenarios covering P0 bugs, base nodes, advanced features,
error scenarios, and edge cases.

Key Changes:
- Added 15 workflow creation test scenarios in create-workflow.test.ts
- Fixed critical MSW interference with real API calls
- Fixed environment loading priority (.env before test defaults)
- Implemented multi-level cleanup with webhook workflow preservation
- Migrated from webhook IDs to webhook URLs configuration
- Added TypeScript type safety fixes (26 errors resolved)
- Updated test names to reflect actual n8n API behavior

Bug Fixes:
- Removed MSW from integration test setup (was blocking real API calls)
- Fixed .env loading order to preserve real credentials over test defaults
- Added type guards for undefined workflow IDs
- Fixed position arrays to use proper tuple types [number, number]
- Added literal types for executionOrder and settings values

Test Coverage:
- P0: Critical bug verification (FULL vs SHORT node type format)
- P1: Base n8n nodes (webhook, HTTP, langchain, multi-node)
- P2: Advanced features (connections, settings, expressions, error handling)
- Error scenarios (documents actual n8n API validation behavior)
- Edge cases (minimal workflows, empty connections, no settings)

Technical Improvements:
- Cleanup strategy preserves pre-activated webhook workflows
- Single webhook URL accepts all HTTP methods (GET, POST, PUT, DELETE)
- Environment-aware credential loading with validation
- Comprehensive test context for resource tracking

All 15 tests passing ✅
TypeScript: 0 errors ✅

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

tests/setup/test-env.ts

@@ -13,17 +13,27 @@ import { existsSync } from 'fs';
 export function loadTestEnvironment(): void {
   // CI Debug logging
   const isCI = process.env.CI === 'true';
-  
+
+  // First, load the main .env file (for integration tests that need real credentials)
+  const mainEnvPath = path.resolve(process.cwd(), '.env');
+  if (existsSync(mainEnvPath)) {
+    dotenv.config({ path: mainEnvPath });
+    if (isCI) {
+      console.log('[CI-DEBUG] Loaded .env file from:', mainEnvPath);
+    }
+  }
+
   // Load base test environment
   const testEnvPath = path.resolve(process.cwd(), '.env.test');
-  
+
   if (isCI) {
     console.log('[CI-DEBUG] Looking for .env.test at:', testEnvPath);
     console.log('[CI-DEBUG] File exists?', existsSync(testEnvPath));
   }
-  
+
   if (existsSync(testEnvPath)) {
-    const result = dotenv.config({ path: testEnvPath });
+    // Don't override values from .env
+    const result = dotenv.config({ path: testEnvPath, override: false });
     if (isCI && result.error) {
       console.error('[CI-DEBUG] Failed to load .env.test:', result.error);
     } else if (isCI && result.parsed) {
@@ -39,9 +49,9 @@ export function loadTestEnvironment(): void {
     dotenv.config({ path: localEnvPath, override: true });
   }
 
-  // Set test-specific defaults
+  // Set test-specific defaults (only if not already set)
   setTestDefaults();
-  
+
   // Validate required environment variables
   validateTestEnvironment();
 }